Flat-panel bacterios count
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Last Update: 2021-01-20
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Source: Internet
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Author: User
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I,
culture
-based and
-reagents
tablet count
gasic fat
, 75% ethanol, phosphate buffer dilution
II, operating procedures
1. Sample preparation
(1) for sterile operation to take representative samples in sterilized containers. If packaged, wipe the packaging opening with 75% ethanol and sample it.
(2) Preparation of sample homogenizer: 25g sample taken in sterile operation, placed in a sterilized homogeneous cup containing 225 ml of thinner, 1-2min in 8000r/min homogeneity, to make 1:10 sample homogenization. If the sample homogeneity time exceeds 2min, the homogeneity cup should be cooled with ice water.
(3) dilution sample homogeneity: 10 ml sterilization
straw
accurate absorption of 1:10 sample homogenization 10 ml, into a 150 ml dilution bottle containing 90 ml of diluent. Shake quickly and mix the sample to make a sample homogeneity of 1:100. When shaking, the amplitude is 30cm, 7s shaking 25 times. Do not touch the tip of the bottle at the tip of the straw in order to absorb sample homogeneity from the container and in future dilution operations. The inhaled liquid should first be above the required scale, and then lift the straw so that its tip leaves the liquid surface and attachs it to the inner wall of the container to adjust the liquid to the required scale.
2. Plate Inoculation
(1) For each sample, select a suitable three consecutive dilution of the sample fluid for plate counting.
(2) using sterilization straw to absorb 1 ml of sample fluid into a suitable mark of the flat dish. Use two flat dishes for each dilution of the sample fluid.
(3) add 12-15 ml plate count agar (about 45 degrees C) to the flat dish. Immediately mix the sample fluid and agar in the pan
the
a full mix. To prevent the mixture from spilling on the flat wall and cover. At the same time, the plate count agar poured into another sterilized flat dish with 1 ml of thinner for blank control. The sample fluid should be poured into the agar culture immediately after adding the flat dish, and each sample should take no more than 20min from the beginning of dilution to the last flat dish.
3. culture
after the agar solidification, the flat dish will be flipped, immediately put into 36±1 degrees C
stration
culture box culture 48±2h. The culture box should maintain a certain humidity, and the weight loss of the 48h cultured agar culture base should not exceed 15%.
4. The number of
on each tablet is counted immediately after the 4.Bacillus count and the record
(1) culture. 25-250 bacteria are in the appropriate range. If the count is not immediate, store the plate at 0-4 degrees C, but not more than 24h.
(2) the operator reviews its own count results on the same tablet, the difference should be within 5%, while others repeat the count of the plate, the difference should be within 10%. Otherwise, the cause should be identified and corrected.
5. Calculate the average number of places per gram
(ml) of the two plates suitable for dilution or the average number of flat bacterios per gram (ml) of dilution by multiplying the average number of flat bacterios per gram (ml) sample.
the record, only when the number of flat bacterios per gram (ml) sample can be set, and the third digit is recorded by rounding. The number of flat bacterios in the sample can also be recorded as an exponential form of 10.
, the results report
report the number of flat-plate bacterios per gram (ml) of samples or the estimated number of flat-panel bacterios.
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